| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <limits.h> |
| #include <mqueue.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <sys/ipc.h> |
| #include <sys/msg.h> |
| #include <sys/sem.h> |
| #include <sys/shm.h> |
| #include <sys/stat.h> |
| #include <unistd.h> |
| |
| #include "clean-ipc.h" |
| #include "dirent-util.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "format-util.h" |
| #include "log.h" |
| #include "macro.h" |
| #include "string-util.h" |
| #include "strv.h" |
| #include "user-util.h" |
| |
| static bool match_uid_gid(uid_t subject_uid, gid_t subject_gid, uid_t delete_uid, gid_t delete_gid) { |
| |
| if (uid_is_valid(delete_uid) && subject_uid == delete_uid) |
| return true; |
| |
| if (gid_is_valid(delete_gid) && subject_gid == delete_gid) |
| return true; |
| |
| return false; |
| } |
| |
| static int clean_sysvipc_shm(uid_t delete_uid, gid_t delete_gid, bool rm) { |
| _cleanup_fclose_ FILE *f = NULL; |
| bool first = true; |
| int ret = 0, r; |
| |
| f = fopen("/proc/sysvipc/shm", "re"); |
| if (!f) { |
| if (errno == ENOENT) |
| return 0; |
| |
| return log_warning_errno(errno, "Failed to open /proc/sysvipc/shm: %m"); |
| } |
| |
| for (;;) { |
| _cleanup_free_ char *line = NULL; |
| unsigned n_attached; |
| pid_t cpid, lpid; |
| uid_t uid, cuid; |
| gid_t gid, cgid; |
| int shmid; |
| |
| r = read_line(f, LONG_LINE_MAX, &line); |
| if (r < 0) |
| return log_warning_errno(errno, "Failed to read /proc/sysvipc/shm: %m"); |
| if (r == 0) |
| break; |
| |
| if (first) { |
| first = false; |
| continue; |
| } |
| |
| if (sscanf(line, "%*i %i %*o %*u " PID_FMT " " PID_FMT " %u " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT, |
| &shmid, &cpid, &lpid, &n_attached, &uid, &gid, &cuid, &cgid) != 8) |
| continue; |
| |
| if (n_attached > 0) |
| continue; |
| |
| if (!match_uid_gid(uid, gid, delete_uid, delete_gid)) |
| continue; |
| |
| if (!rm) |
| return 1; |
| |
| if (shmctl(shmid, IPC_RMID, NULL) < 0) { |
| |
| /* Ignore entries that are already deleted */ |
| if (IN_SET(errno, EIDRM, EINVAL)) |
| continue; |
| |
| ret = log_warning_errno(errno, |
| "Failed to remove SysV shared memory segment %i: %m", |
| shmid); |
| } else { |
| log_debug("Removed SysV shared memory segment %i.", shmid); |
| if (ret == 0) |
| ret = 1; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int clean_sysvipc_sem(uid_t delete_uid, gid_t delete_gid, bool rm) { |
| _cleanup_fclose_ FILE *f = NULL; |
| bool first = true; |
| int ret = 0, r; |
| |
| f = fopen("/proc/sysvipc/sem", "re"); |
| if (!f) { |
| if (errno == ENOENT) |
| return 0; |
| |
| return log_warning_errno(errno, "Failed to open /proc/sysvipc/sem: %m"); |
| } |
| |
| for (;;) { |
| _cleanup_free_ char *line = NULL; |
| uid_t uid, cuid; |
| gid_t gid, cgid; |
| int semid; |
| |
| r = read_line(f, LONG_LINE_MAX, &line); |
| if (r < 0) |
| return log_warning_errno(r, "Failed to read /proc/sysvipc/sem: %m"); |
| if (r == 0) |
| break; |
| |
| if (first) { |
| first = false; |
| continue; |
| } |
| |
| if (sscanf(line, "%*i %i %*o %*u " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT, |
| &semid, &uid, &gid, &cuid, &cgid) != 5) |
| continue; |
| |
| if (!match_uid_gid(uid, gid, delete_uid, delete_gid)) |
| continue; |
| |
| if (!rm) |
| return 1; |
| |
| if (semctl(semid, 0, IPC_RMID) < 0) { |
| |
| /* Ignore entries that are already deleted */ |
| if (IN_SET(errno, EIDRM, EINVAL)) |
| continue; |
| |
| ret = log_warning_errno(errno, |
| "Failed to remove SysV semaphores object %i: %m", |
| semid); |
| } else { |
| log_debug("Removed SysV semaphore %i.", semid); |
| if (ret == 0) |
| ret = 1; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int clean_sysvipc_msg(uid_t delete_uid, gid_t delete_gid, bool rm) { |
| _cleanup_fclose_ FILE *f = NULL; |
| bool first = true; |
| int ret = 0, r; |
| |
| f = fopen("/proc/sysvipc/msg", "re"); |
| if (!f) { |
| if (errno == ENOENT) |
| return 0; |
| |
| return log_warning_errno(errno, "Failed to open /proc/sysvipc/msg: %m"); |
| } |
| |
| for (;;) { |
| _cleanup_free_ char *line = NULL; |
| uid_t uid, cuid; |
| gid_t gid, cgid; |
| pid_t cpid, lpid; |
| int msgid; |
| |
| r = read_line(f, LONG_LINE_MAX, &line); |
| if (r < 0) |
| return log_warning_errno(r, "Failed to read /proc/sysvipc/msg: %m"); |
| if (r == 0) |
| break; |
| |
| if (first) { |
| first = false; |
| continue; |
| } |
| |
| if (sscanf(line, "%*i %i %*o %*u %*u " PID_FMT " " PID_FMT " " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT, |
| &msgid, &cpid, &lpid, &uid, &gid, &cuid, &cgid) != 7) |
| continue; |
| |
| if (!match_uid_gid(uid, gid, delete_uid, delete_gid)) |
| continue; |
| |
| if (!rm) |
| return 1; |
| |
| if (msgctl(msgid, IPC_RMID, NULL) < 0) { |
| |
| /* Ignore entries that are already deleted */ |
| if (IN_SET(errno, EIDRM, EINVAL)) |
| continue; |
| |
| ret = log_warning_errno(errno, |
| "Failed to remove SysV message queue %i: %m", |
| msgid); |
| } else { |
| log_debug("Removed SysV message queue %i.", msgid); |
| if (ret == 0) |
| ret = 1; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int clean_posix_shm_internal(const char *dirname, DIR *dir, uid_t uid, gid_t gid, bool rm) { |
| struct dirent *de; |
| int ret = 0, r; |
| |
| assert(dir); |
| |
| FOREACH_DIRENT_ALL(de, dir, goto fail) { |
| struct stat st; |
| |
| if (dot_or_dot_dot(de->d_name)) |
| continue; |
| |
| if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) { |
| if (errno == ENOENT) |
| continue; |
| |
| ret = log_warning_errno(errno, "Failed to stat() POSIX shared memory segment %s/%s: %m", |
| dirname, de->d_name); |
| continue; |
| } |
| |
| if (S_ISDIR(st.st_mode)) { |
| _cleanup_closedir_ DIR *kid = NULL; |
| |
| kid = xopendirat(dirfd(dir), de->d_name, O_NOFOLLOW|O_NOATIME); |
| if (!kid) { |
| if (errno != ENOENT) |
| ret = log_warning_errno(errno, "Failed to enter shared memory directory %s/%s: %m", |
| dirname, de->d_name); |
| } else { |
| r = clean_posix_shm_internal(de->d_name, kid, uid, gid, rm); |
| if (r < 0) |
| ret = r; |
| } |
| |
| if (!match_uid_gid(st.st_uid, st.st_gid, uid, gid)) |
| continue; |
| |
| if (!rm) |
| return 1; |
| |
| if (unlinkat(dirfd(dir), de->d_name, AT_REMOVEDIR) < 0) { |
| |
| if (errno == ENOENT) |
| continue; |
| |
| ret = log_warning_errno(errno, "Failed to remove POSIX shared memory directory %s/%s: %m", |
| dirname, de->d_name); |
| } else { |
| log_debug("Removed POSIX shared memory directory %s", de->d_name); |
| if (ret == 0) |
| ret = 1; |
| } |
| } else { |
| |
| if (!match_uid_gid(st.st_uid, st.st_gid, uid, gid)) |
| continue; |
| |
| if (!rm) |
| return 1; |
| |
| if (unlinkat(dirfd(dir), de->d_name, 0) < 0) { |
| |
| if (errno == ENOENT) |
| continue; |
| |
| ret = log_warning_errno(errno, "Failed to remove POSIX shared memory segment %s: %m", de->d_name); |
| } else { |
| log_debug("Removed POSIX shared memory segment %s", de->d_name); |
| if (ret == 0) |
| ret = 1; |
| } |
| } |
| } |
| |
| return ret; |
| |
| fail: |
| return log_warning_errno(errno, "Failed to read /dev/shm: %m"); |
| } |
| |
| static int clean_posix_shm(uid_t uid, gid_t gid, bool rm) { |
| _cleanup_closedir_ DIR *dir = NULL; |
| |
| dir = opendir("/dev/shm"); |
| if (!dir) { |
| if (errno == ENOENT) |
| return 0; |
| |
| return log_warning_errno(errno, "Failed to open /dev/shm: %m"); |
| } |
| |
| return clean_posix_shm_internal("/dev/shm", dir, uid, gid, rm); |
| } |
| |
| static int clean_posix_mq(uid_t uid, gid_t gid, bool rm) { |
| _cleanup_closedir_ DIR *dir = NULL; |
| struct dirent *de; |
| int ret = 0; |
| |
| dir = opendir("/dev/mqueue"); |
| if (!dir) { |
| if (errno == ENOENT) |
| return 0; |
| |
| return log_warning_errno(errno, "Failed to open /dev/mqueue: %m"); |
| } |
| |
| FOREACH_DIRENT_ALL(de, dir, goto fail) { |
| struct stat st; |
| char fn[1+strlen(de->d_name)+1]; |
| |
| if (dot_or_dot_dot(de->d_name)) |
| continue; |
| |
| if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) { |
| if (errno == ENOENT) |
| continue; |
| |
| ret = log_warning_errno(errno, |
| "Failed to stat() MQ segment %s: %m", |
| de->d_name); |
| continue; |
| } |
| |
| if (!match_uid_gid(st.st_uid, st.st_gid, uid, gid)) |
| continue; |
| |
| if (!rm) |
| return 1; |
| |
| fn[0] = '/'; |
| strcpy(fn+1, de->d_name); |
| |
| if (mq_unlink(fn) < 0) { |
| if (errno == ENOENT) |
| continue; |
| |
| ret = log_warning_errno(errno, |
| "Failed to unlink POSIX message queue %s: %m", |
| fn); |
| } else { |
| log_debug("Removed POSIX message queue %s", fn); |
| if (ret == 0) |
| ret = 1; |
| } |
| } |
| |
| return ret; |
| |
| fail: |
| return log_warning_errno(errno, "Failed to read /dev/mqueue: %m"); |
| } |
| |
| int clean_ipc_internal(uid_t uid, gid_t gid, bool rm) { |
| int ret = 0, r; |
| |
| /* If 'rm' is true, clean all IPC objects owned by either the specified UID or the specified GID. Return the |
| * last error encountered or == 0 if no matching IPC objects have been found or > 0 if matching IPC objects |
| * have been found and have been removed. |
| * |
| * If 'rm' is false, just search for IPC objects owned by either the specified UID or the specified GID. In |
| * this case we return < 0 on error, > 0 if we found a matching object, == 0 if we didn't. |
| * |
| * As special rule: if UID/GID is specified as root we'll silently not clean up things, and always claim that |
| * there are IPC objects for it. */ |
| |
| if (uid == 0) { |
| if (!rm) |
| return 1; |
| |
| uid = UID_INVALID; |
| } |
| if (gid == 0) { |
| if (!rm) |
| return 1; |
| |
| gid = GID_INVALID; |
| } |
| |
| /* Anything to do? */ |
| if (!uid_is_valid(uid) && !gid_is_valid(gid)) |
| return 0; |
| |
| r = clean_sysvipc_shm(uid, gid, rm); |
| if (r != 0) { |
| if (!rm) |
| return r; |
| if (ret == 0) |
| ret = r; |
| } |
| |
| r = clean_sysvipc_sem(uid, gid, rm); |
| if (r != 0) { |
| if (!rm) |
| return r; |
| if (ret == 0) |
| ret = r; |
| } |
| |
| r = clean_sysvipc_msg(uid, gid, rm); |
| if (r != 0) { |
| if (!rm) |
| return r; |
| if (ret == 0) |
| ret = r; |
| } |
| |
| r = clean_posix_shm(uid, gid, rm); |
| if (r != 0) { |
| if (!rm) |
| return r; |
| if (ret == 0) |
| ret = r; |
| } |
| |
| r = clean_posix_mq(uid, gid, rm); |
| if (r != 0) { |
| if (!rm) |
| return r; |
| if (ret == 0) |
| ret = r; |
| } |
| |
| return ret; |
| } |
| |
| int clean_ipc_by_uid(uid_t uid) { |
| return clean_ipc_internal(uid, GID_INVALID, true); |
| } |
| |
| int clean_ipc_by_gid(gid_t gid) { |
| return clean_ipc_internal(UID_INVALID, gid, true); |
| } |
